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Another Step Towards Graphene Semiconductors

Posted by samzenpus on from the next-step dept.

derGoldstein writes "Ars has an article up about the two latest 'papers demonstrating that, if you change the way the graphene stacks, you obtain a voltage-controlled bandgap ... Between these two papers, a fairly complete understanding of the bandgap behavior in three-layer graphene has been obtained, leaving only the challenge of making the stuff.'"

33 comments

  1. Acceptence by Anonymous Coward · · Score: -1

    I for one accept our graphene based overlords :P

  2. Graphene == dead end :-( by dev324 · · Score: -1, Troll

    The point it is that indeed its very hard to make graphene gates
    In fact nobody have yet succeded making even simple integrated circuit out of them.
    Link above explains huge challenges involved and practical impossibility of graphene integrated circuits.

    1. Re:Graphene == dead end :-( by miknix · · Score: -1, Offtopic

      Congratulations, you just ruined my day!

    2. Re:Graphene == dead end :-( by Anonymous Coward · · Score: -1

      That certainly illustrates a gaping hole in the technology!

    3. Re:Graphene == dead end :-( by peragrin · · Score: 1

      That because they are missing the final step of massively heating and compressing the graphene to create diamond circuits . After that we will have crystal computers and the future will be now.

      --
      i thought once I was found, but it was only a dream.
    4. Re:Graphene == dead end :-( by Anonymous Coward · · Score: -1

      Don't blame the messenger.

    5. Re:Graphene == dead end :-( by slack_justyb · · Score: -1, Offtopic

      Why is this marked troll? Is suddenly a healthy does of reality mean your a troll on Slashdot?! Look graphene is an incredibly rare substance and we have yet to figure out how to manufacture large amounts of the stuff to overcome that rare part. There are a lot of papers out there that address all the amazing stuff that can be done with graphene but until there is an appreciable amount of the stuff its all pipe dreams.

      So I fail to see why, when someone points out this fact, they get modded troll? This is not to say the technology is flawed or a bad idea or what-have-you, it's just outside of our reach and until we overcome the production problem, it will remain so. This draws so many parallels to the current debate of oil as the basis of our motor fuels. I love the idea of electric cars, but we're not totally there yet. There is a lot that needs to be figured out, infrastructure, manufacturers, TOC, energy production... Without getting too off-topic here, the same applies. The technology sounds awesome but we have yet to make it viable. Sometimes I think it just infuriates Slashdotters that no matter how clever humanity gets, we still have to convince the idiots to go along with us as well or we get zero traction on things.

    6. Re:Graphene == dead end :-( by samael · · Score: 1, Informative

      They are being modded troll because it links to a goatse.cx image...

      --
      My Journal
    7. Re:Graphene == dead end :-( by davetv · · Score: -1, Offtopic

      to mods : well I thought it was funny

    8. Re:Graphene == dead end :-( by slack_justyb · · Score: 0

      Ah, well I guess that explains it.

    9. Re:Graphene == dead end :-( by Anonymous Coward · · Score: 0

      Obviously you didn't STFSA.

    10. Re:Graphene == dead end :-( by Anonymous Coward · · Score: 0

      fuck you you fucking fuck

  3. The substance that does it all by neokushan · · Score: 2, Funny

    Honestly, is there anything Graphene CAN'T do? I'm just waiting for an article to appear that states Graphene may be a cure for Cancer and AIDS rolled into one.
    And then I'm fully expecting another article stating that it's more deadly than asbestos.

    --
    +1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
    1. Re:The substance that does it all by Anonymous Coward · · Score: 1

      And then I'm fully expecting another article stating that it's more deadly than asbestos.

      I think you'll find that one is nanotubes.

    2. Re:The substance that does it all by gutnor · · Score: 0

      Graphene is just the new Carbon Nanotube. The new silver bullet to get a grant.

    3. Re:The substance that does it all by Anonymous Coward · · Score: 0

      Or to get Space Nutters excited about colonizing the universe. With lifeforms that have maybe 10-20 years of useful life. In a universe that's billions of years old, we'll never find the way to extend our life span, and we never should. But we should build gigantic rockets that will require a significant fraction of the planet's resources for decades so a few A-type personalities can go forth, FOR THE SPECIES!

      How noble! How grandiose! How selfless!

    4. Re:The substance that does it all by neokushan · · Score: 1, Redundant

      Yes indeed, why should we bother progressing? It's just a waste of time. Better stick with what we have now, because that's going to work out better.

      --
      +1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
    5. Re:The substance that does it all by Chuck+Chunder · · Score: 2

      Honestly, is there anything Graphene CAN'T do?

      Yes.

      Fortunately we have lasers for those situations.

      --
      Boffoonery - downloadable Comedy Benefit for Bletchley Park
    6. Re:The substance that does it all by SectionTwelve · · Score: -1

      Honestly, is there anything Graphene CAN'T do? I'm just waiting for an article to appear that states Graphene may be a cure for Cancer and AIDS rolled into one.
      And then I'm fully expecting another article stating that it's more deadly than asbestos.

      There are lots of things graphene cannot do. For instance, it can't make a sandwich for me and bring me beer.

    7. Re:The substance that does it all by Anonymous Coward · · Score: 0

      Who said that? What does "progress" have to do with doing the same old rocket trips for the last 40 years? Oh, wait, you think there's some magical gap in our understanding of physics that will allow us to colonize the universe, but at the same time it won't allow us to extend our lifespan? Help me understand your point of view.

      Mine is simple. There are very real, hard limits to the amount of energy we can put in one place, and how much thrust we can make. We basically make fire in a tube and make it go out the bell end, so the pointy end can move. This is at the very limits of our technology and engineering capacity. To think otherwise shows utter ignorance, which is perplexing in an era of instant information access.

      On the other hand, I see no real physical limit to how old a human can be, since the "age" of a person isn't "stored" anywhere in atoms. A carbon atom in an elderly person is the same as any other carbon atom. So "age" is just a pattern. It won't require stupendous amounts of energy or impossible materials to reset patterns. It will be very complex, but not physically impossible.

      After all, *you* organized yourself out of a single cell. With atoms and chemical energy. To think that we won't find molecules or molecular programs to explain, stop and reverse aging is crazy.

    8. Re:The substance that does it all by gtbritishskull · · Score: 0

      Yet.

    9. Re:The substance that does it all by Nadaka · · Score: 0

      And that happens to be graphene rolled into one.

    10. Re:The substance that does it all by sjames · · Score: 0

      I'm sure we'll eventually come up with some way to bond graphene to shark skin, then it will be complete.

    11. Re:The substance that does it all by Anonymous Coward · · Score: 0

      Graphene is a very long way from being manufactured. That's something graphene can't do.

      You don't just "invent something" and have it automagically 1) scale up to production volumes, and 2) have what you manufactured still function 1, 2, 5 or 10 years into the future once it's been sold.

      Dealing with just those two show-shopping reality details will easily take 10-20 years once they finally figure out the specific device structure that does something useful. You can't even start working on those things while that part of the story is still a moving target (which is absolutely still is). When you start seeing the same basic device "drawing" appear in publication for a year or two, then you know things are finally (and only maybe) reaching the point when you can finally start the 10-20 year development clock. This is still in the research phase. You do remember that R&D is research and development.

      Now the researcher probably know this pretty well (unless they are hopelessly incompetent), but the press office toads at universities and corporations aren't usually that smart nor that ethical so they'll happily lie and tell half truths just to goose their organization's stature or stock.

      BTW I work in advanced semiconductor and nanoelectronic device technologies. I'm an engineer so I deal with practical realities and schedules not theoretical timelines and wishful thinking.

    12. Re:The substance that does it all by SectionTwelve · · Score: 0

      Love how this was modded "off topic" even though it clearly mentions graphene, which WAS the topic.

      Go, go typical /.'er with too much time and too many mod points on their hands!

  4. 2 layer vs 3 layer by vlm · · Score: 4, Interesting

    I'm having trouble peering thru the journalist filter and not finding any other primary sources.

    To a first approximation, the point seems to be that what we used to be able to do with bi-layer two layer graphene, we can now do with tri-layer three layer graphene. Um, OK, thats nice but not "new".

    http://arxiv.org/PS_cache/arxiv/pdf/1001/1001.5213v1.pdf

    So, aside from purely theoretical "thats interesting, just for the sake of physics", what is the point? More durable, better electrical properties, easier to make (thats hard to believe), stronger, easier to customize and control the above, or what? Someone with access to Nature-Physics to read the actual papers could probably respond?

    The article is really poor because it tapdances around the important story which is what I list above.

    --
    "Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
    1. Re:2 layer vs 3 layer by John+Hasler · · Score: 2

      I'm having trouble peering thru the journalist filter and not finding any other primary sources.

      I thought it was fairly clear that this demonstrates the existence of a bandgap that cannot be attributed to substrate effects or contaminants.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    2. Re:2 layer vs 3 layer by gstrickler · · Score: 4, Informative

      To a first approximation, the point seems to be that what we used to be able to do with bi-layer two layer graphene, we can now do with tri-layer three layer graphene. Um, OK, thats nice but not "new"

      No, bi-layer graphene can have a band-gap, but it's not controllable, so it can't be used to make a transistor. Conventionally stacked tri-layer graphene has the same problem. What is new is that by changing the way three graphene layers are stacked allows creating a voltage controlled band-gap, which allows for the creation of a transistor.

      --
      make imaginary.friends COUNT=100 VISIBLE=false
  5. A tunable photodetector by John+Hasler · · Score: 1

    One group observed the photoconductivity of their graphene sheets as a function of wavelength and applied voltage. They showed that the oddly stacked three layer graphene sheets would generate a larger current for particular colors. That is, the light was exciting electrons out of bound states and into conducting states, indicating the presence of a bandgap. Furthermore, this color changed depending on the applied voltage, indicating that the bandgap was changing with the voltage.

    A voltage tunable photodector. Useful.

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    1. Re:A tunable photodetector by marcosdumay · · Score: 1

      Probably just as usefull as any normal phototransistor out there.

      But this one is a transistor, and made of graphene, a material with very low electrical and thermic resistence.

      --
      Rethinking email
    2. Re:A tunable photodetector by John+Hasler · · Score: 2

      > Probably just as usefull as any normal phototransistor out there.

      Normal phototransistors don't have adjustable bandgaps.

      > ...a material with very low electrical and thermic resistence.

      And thus also potentially much faster than exisitng photodetectors.

      --
      Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    3. Re:A tunable photodetector by mozumder · · Score: 0

      This could help improve dynamic range on image sensors.

  6. It's the new nanotubes! by Anonymous Coward · · Score: 0

    Couple years ago, nanotubes this, nanotubes that, now everyone who's anyone knows that nanotubes are SO last thursday. Graphene is THE hot carbon structure these day. If you go around with all your nanotubes it's almost as bad as those bucky-ball n00bs.